The mechanically exfoliated ultrathin 3R α-In₂Se₃ nanosheets were transferred onto a SiO₂/Si substrate. Using atomic force microscopy, it was confirmed that the transferred α-In₂Se₃ transferred had a thickness of 15–120 nm. The thickness-dependence of Raman peaks of \({E}^{2}\), \({A}_{1}^{1}\), \({E}^{4}\), and \({A}_{1}^{2}\) was observed from the Raman spectra. Moreover, the measured photoluminescence peak values in the range of 869–895 nm indicate a blue shift as the thickness decreases. The field-effect transistor based on α-In₂Se₃ exhibited an n-type semiconductor behavior. From the transfer curve at gate voltage of 10 V, the derived values of the mobility and ON/OFF ratio are 24.26 cm² V^− 1 s^− 1 and 1.84, respectively. In addition, it was confirmed that the 3R α-In₂Se₃ layers had a high photoresponsivity of up to approximately 34,500 A/W under illumination (\(\lambda\) = 750 nm).

Graphical abstract

中文翻译：

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α-In2Se3 纳米片的机械剥离菱面体 (3R) 结构特征

机械剥离的超薄 3R α-In ₂ Se ₃纳米片被转移到 SiO ₂ /Si 基板上。使用原子力显微镜确认转移的α-In ₂ Se ₃的厚度为15-120nm。\({E}^{2}\)、\({A}_{1}^{1}\)、\({E}^{4}\)和\的拉曼峰的厚度依赖性({A}_{1}^{2}\)从拉曼光谱中观察到。此外，在 869–895 nm 范围内测得的光致发光峰值表明随着厚度的减小发生蓝移。_{基于α-In 2} Se ₃的场效应晶体管表现出 n 型半导体行为。从栅极电压为 10 V 时的转移曲线，迁移率和开/关比的导出值分别为 24.26 cm ² V ^{- 1}  s ^{- 1}和 1.84。此外，已证实 3R α-In ₂ Se ₃层在光照下具有高达约 34,500 A/W 的高光响应性 ( \(\lambda\) = 750 nm)。

图形概要